Heat exchanger



June 9, 1953 E. w. KAISER 2,641,451

HEAT EXCHANGER Filed Nov. 4, 1950 INVENTOR.

Eda/ma W/iaEe Z Patented June 9 1953 UNITED STATES PATENT OFFICE HEATEXCHANGER Edward- Kaiser, Chicago, Ill.

Application November 4, 1950, Serial No, 194,173

4- Claims. 1

This invention relates, generally, to heat exchangers, and it hasparticular relation to such devices for maintaining a liquid in a tankand in a pipe connected thereto at an elevated temperature so as tomaintain the contents thereof in the liquid state, which contents wouldbe solid or viscous at room temperature.

Among the objects of this invention are: To circulate a heated fluid,such as steam or hot water, around the pipe through which the liquidflows from or to the tank in order to maintain not only such liquid butalso the liquid in the tank at the elevated temperature; to direct theflow of the heated fluid so that it follows a circuitous path; toprovide a relatively great surface Within the tank in contact with theliquid therein on the one hand and maintained at the elevatedtemperature on the other hand; to prevent intermingling between theliquid in the tank and pipe and the heated fluid; and to connect such aheat exchanger either to a jacketed or non-jacketed piping system.

Other objects of this invention will, in part, be obvious and in partappear hereinafter.

This invention is disclosed in the embodiments. thereof shown in theaccompanying drawings and it comprises the features of construction,combination of elements and arrangement of parts which will beexemplified in the constructions hereinafter set forth and the scope ofthe application of which will be indicated in the ap pended claims.

For a more complete understanding of thenature and scope of thisinvention, reference can be had to the following detailed" description,taken together with the accompanying drawings, in which:

Figure 1 is a view, partly in side elevation and partly in section,illustrating one heat exchangerconstructed in accordance with thisinvention and applied to a tank the contents of which are to bemaintained in the-liquid state;

Figure 2 is a view, similar to Figure 1, showing a modified form of theheat exchanger and how it can be adapted to be connected to a jacketedconduit system such as that disclosed in. my copending applicationSerial No. 47,851, filed September 4, 1948;

Figure 3 is a detail sectional view taken generally along the line 3-3of Figure 2;

Figure 4 is a View, similar to Figure 2, illustrat ing how the heatexchanger of the present inven-.-

tion can be connected to a non-jacketed system. Referring nowparticularly to Figure 1 of the drawings, it will be observed that thereferencecharacter In designates, generally, a tank, only a portion ofwhich is shown, that may be adapt ed for receiving a liquid, such aswax, which is solid at room temperature and must. be main-- tained at anelevated temperature in order to keep it in the liquid state. It will beunderstood that other materials. which are similar in nature-v to waxmay be received and heated in the tank: l0. It is. contemplated thatviscous materialsalso may be used and that: they are. of such naturethat they must be maintained at an ele vated temperature in order topermit them. to flow readily into orout of the: tank lat. One of. thetank walls is indicated: at. H; and it interfits with a shell l2 whichmay be. cylindrical. The wall I! and shell l2 may be secured. togetherin liquid tight. relation by any suitable means such as by welding l3..

In accordance. with this invention the. means; employed for maintainingthe liquid in the. tank It in the liquid state is also. employed formain taining' the liquid in the inlet or outlet. pipe to.- the tank. H3in. the liquid state. For this purpose a tank nipple I4 is employed and,as. shown, it comprises a. shortv length. of pipe; which, extendsthrough a suitable aperture in the; wall M for a short. distance; Thetank nipple I4; is. secured in fluid tight relation to the-wall, Ill" bywelding- I5. The outer end of the tank nipple. His securedby welding 16.to a. radially extending flange H. The tank nipple l4. and flange l'1-,when arrangedas described, constitute an. integral; part: of: the. tankwall It. The remaining partsofi the heat, exchan r: constructed inaccordance with this;

invention are; readily removable; from the. tank.

I0 in a manner which will be apparent presently.

In. order to. flow the liquid: into or out. of the tank I01 aninnerpipe. Z'GisempIQved. Thepipe 20;. as illustrated; is; formed of. metal,such asi stainless. steel, steel, or; the like. At its inner. end itopens into the tank It andlisbelow the suriace. 0f the liquid therein.The inner pipejlliextendscentrally 0t thev tank nipple IA and: is; held,in spaced relation by means which will; beadescribed pre ently;

Surrounding the inner n ne. 2B -ar1d. ex ending a substantial distanceinto.- the; tank In; is: an outer; p pe. 2t. This. p pe, like. the:inner; pipe; 20 is; formed of metal such as s ainless, steel, steel or:

the. like... It. has a large. surfacewhich contac s the; liquid, irr thetank. .50- .and thus providesexcellent heat transfer medium. for. a.heated: fluid which is. circulated through it. Since. the outer pipe 21and the. inner pipe 211 project into the; tank I 0; a substantialdistance it. is desirable to; provide a support: therefor near the innerends thereon For this purposeia pedestaliniisi emrployed. With a View toenclosing the inner end of the outer pipe 2| an annular plate 23 isemployed. As indicated at 24 the plate 23 is welded to the outer surfaceof the inner pipe 20. The periphery of the plate 23 is welded bysuitable means to the inner end of the outer pipe 2 I. The constructionthus described provides an annular space 25 within the outer pipe 2| andaround the inner pipe 20 through which a heated fluid, such as steam,can be circulated for the purpose not only of heating the liquid in thetank I but also for maintaining the liquid within the inner pipe 20 inthe liquid state so that it will flow freely therethrough.

The outer pipe 2| extends centrally through the tank nipple l4 andthrough the flange I1 welded thereto. By means of welding 26 the outerpipe 2| is secured to a flange 21 which abuts the flange l1 and to whichit is secured by suitable through bolts (not shown). It will beunderstood that a suitable gasket may be provided between the flanges I1and 21 and between similar flanges described hereinafter in order toprovide a fluid tight construction. It will be understood that theflange 2'| welded at 26 to the outer pipe 2| constitutes closure meansfor the outer end of the tank nipple I4 and between it and the outerpipe 2 I. This also constitutes a mechanical support for the outer endof the outer pipe 2 At its extreme outer end the outer pipe 2| issecured by welding 28 to a radial flange 29. Where the inner pipe 20 isnot arranged to extend into a jacketed conduit system, means areprovided here for making a, sealed connection between the inner pipe 20and the outer pipe' 2|. For this purpose the flange 29 is secured, as bybolts, to another flange 30 which forms a part of a stuffing box that isindicated, generally, at 3|. The flange 30 and stuifing box 3|constitute closure means between the outer end of the outer pipe 2| andthe portion of the inner pipe 20 that extends centrally therethrough.

As indicated hereinbefore the space 25 between the inner pipe 20 and theouter pipe 2| is arranged to be filled with a heated fluid. For thispurpose an inlet conduit 32 and an outlet conduit 33 are connected tothe outer pipe 2| between the flanges 21 and 29 as illustrated. Steam iscaused to flow through the conduits 32 and 33 in the direction indicatedby the arrows for circulating the heated fluid through the space 25 toheat the liquid in the tank I0 and also to maintain the liquid withinthe inner pipe 20 in the liquid state.

It will be understood that a heated fluid, such as steam, willcompletely fill the space 25. Under proper conditions heat will beextracted from the steam within the space 25 and it will condense sothat the condensate will flow out through the conduit 33.

In Figure 2 of the drawings, a heat exchanger constructed generallysimilar to that shown in Figure l and described above is illustrated. Inorder to improve the circulation of the heated fluid between the innerpipe 20 and the outer pipe 2| in the space 25, there is provided anintermediate pipe 36. It will be observed that the intermediate pipe 36is located between the inner pipe 20 and the outer pipe 2| and isconcentric therewith. The intermediate pipe 36 projects through theouter end of the outer pipe 2| and through the nipple I4 which, in thisinstance, is provided with threads |6 for receiving the flange IT. Theintermediate pipe 36 is secured by welding 31 to a flange 30' which, asdescribed hereinbefore, may be secured to the flange 29 by suitablebolts. The flange 30 constitutes a closure means between the outer pipe2| and the intermediate pipe 36. It will be observed that the inner endof the intermediate pipe 36 is spaced, as indicated at 38, from theextreme inner end of the outer pipe 2| or the plate 23. The space 38permits the circulation of the heated fluid from the inside of theintermediate pipe 36 where it is in intimate contact with the outside ofthe inner pipe 2|! to the outside thereof and in intimate contact withthe inner surface of the outer pipe 2|. It is noted here that the plate23 is secured about its outer periphery by welding 24' to the inner endof the outer pipe 2|. Also it will be noted that the flange 29 issecured by threads 28' onto the outer end of the outer pipe 2| At itsextreme outer end the intermediate pipe 36 is secured by welding 39 to aflange 40. It is desirable to seal off the space between the outer endof the intermediate pipe 36 and the outer surface of the inner pipe 20.For this purpose a plate 4| is employed. As shown more clearly in Figure3 the plate 4| has a relatively close fit with the outer surface of theinner pipe 20 although preferably it is not securely attached thereto.The sliding fit thus provided serves to contain the heated fluid whichis circulated through the inlet and outlet conduits 32 and 33 to theintermediate pipe 35. It is here noted that the inlet conduit 32 isconnected to the intermediate pipe 36 while the outlet conduit 33remains connected to the outer pipe 2|. Thus the heated fluid flows intothe intermediate pipe 36 and around the exterior of the inner pipe 2|].It flows through the space 38 and into the portion of the space 25outside of the intermediate pipe 36 and thence to the outlet conduit 33.

It will be noted that the plate 4|, which is apertured centrally toreceive the inner pipe 20, is clamped between the flange 40 and a flange42 that is secured by welding 43' to one end of a jacket 44. The jacket44 constitutes a part of a jacketed conduit system the details of whichare set forth more completely in the copending application abovereferred to. For present purposes it is merely pointed out that thejacket 44 is spaced from the inner pipe 2|] so as to provide an annularspace 45 therearound through which a heated fluid, such as steam or hotwater, can be circulatedfor maintaining the liquid within the inner pipe20 in the liquid state. A conduit 46 may be connected to the jacket 44to form a part of the heated fluid circulating system. The heatexchanger illustrated in Figure 4 is generally similar to thatillustrated in Figure 2 and described above. It differs in that thethreaded connections H5 and 28' are not employed and welding issubstituted therefor. Another distinction is that the stufling box 3|described above in connection with Figure 1 is employed, since the innerpipe 2|] in this modification does not extend into a jacketed conduitsystem.

In the heat exchangers shown in Figures 1, 2 and 4 the inner pipe 2|l isanchored by the plate 23 to the adjacent inner end of the outer pipe 2|.The outer end of the outer pipe 2| is anchored through the flanges 21and I! and the pipe nipple l4 or M to the wall'||. Thus the outer pipe2| expands inwardly of the tank I0 and carries with it the inner pipe20-. The latter is free to move at its outer end since it extendsthrough the which it is slidable.

When the intermediate pipe 36 is employed, as

shown in Figures 2 and 4 to provide a counter-' flow of the heatingmedium through the outer pipe 2| and around the inner pipe 20, theintermediate pipe 36 is anchored at its outer end to the wall H whileits inner end is free to expand inwardly of the tank In. Thisconstruction permits independent expansion and contraction of the pipes2B, 2! and 36 on change in temperature While maintaining fluid tight theconnections therebetween and with the tank I ll. The heating medium fromthe inlet pipe 32 first contacts the inner pipe 20 and, While flowingthrough the intermediate pipe 36, transfers some of the heat in it tothe liquid in the inner pipe 29. During its counterflow between theintermediate pipe 33 and the outer pipe 21 additional heat is removedfrom the heating medium and is transferred to the surrounding liquid inthe tank In.

Since certain further changes can be made in the foregoing constructionsand different embodiments of the invention can be made without departingfrom the spirit and scope thereof, it is intended that all matter shownin the accompanying drawings and described hereinbefore shall beinterpreted as illustrative and not in a limiting sense.

What is claimed as new is:

1. For combination with a tank containing a liquid to be maintained atan elevated temperature, a tank nipple for connection to a wall of thetank, an inner pipe extending through said tank nipple and opening intothe tank through which the liquid therein can flow, an outer pipeextending through and having sealed connection to said tank nipple andsurrounding and spaced from said inner pipe, an intermediate pipeextending into and having sealed connection to said outer pipe outsideof said tank nipple, said intermediate pipe being spaced from said innerand outer pipes and constituting a battle in the space therebetween,closure means within the tank between said outer and inner pipes,closure means without said tank between said intermediate an innerpipes, and conduit means connected to said outer and intermediate pipeswithout the tank for circulating through said space between said innerand outer pipes as directed by said baflie a heated fluid formaintaining the liquid in the tank and in said inner pipe at theelevated temperature.

2. For combination with a tank containing a liquid to be maintained atan elevated temperature, a tank nipple for connection to a wall of thetank, an inner pipe extending through said tank nipple into the tank fora substantial distance and opening into the same through which theliquid therein can flow, an outer pipe having sealed connection to andextending through said tank nipple and into said tank where asubstantial portion of its outer surface contacts the liquid therein,said outer pipe surrounding and spaced from said inner pipe, anintermediate pipe extending into and having sealed connection to saidouter pipe outside of said tank nipple, said intermediate pipe beingspaced from said inner and outer pipes and constituting a bafiie in thespace therebetween, closure means within the tank between said outer andinner pipes, closure means without said tank between said intermediateand inner pipes, and conduit means connected to said outer andintermediate pipes without the tank for circulating through said spacebetween said inner and outer pipes as directed by said baflle a heatedfluid for maintaining the liquid in the tank and in said inner pipe atthe elevated temperature.

3. For combination with a tank containing a liquid to be maintained atan elevated temperature, a tank nipple for connection to and extendingthrough a wall of the tank, an inner pipe extending centrally throughsaid tank nipple into the tank for a substantial distance and openinginto the same through which the liquid therein can flow, an outer pipespaced centrally from and having sealed connection to said tank nippleand extending into said tank Where a substantial portion of its outersurface contacts the liquid therein, said outer pipe surrounding andspaced from said inner pipe, an intermediate pipe extending into andhaving sealed connection to said outer pipe outside of said tank nipple,said intermediate pipe being spaced from said inner and outer pipes andconstituting a baffle in the space therebetween, closure means withinthe tank between said outer and inner pipes, closure means without saidtank between said intermediate and inner pipes, and conduit meansconnected to said outer and intermediate pipes without the tank forcirculating through said space between said inner and outer pipes asdirected by said baffle a heated fluid for maintaining the liquid in thetank and in said inner pipe at the elevated temperature.

4. For combination with a tank containing a liquid to be maintained atan elevated temperature, a tank nipple for connection to a wall of thetank, an inner pipe extending through said tank nipple and opening intothe tank through which the liquid therein can flow, an outer pipeextending through and having sealed connection to said tank nipple andsurrounding and spaced from said inner pipe, an intermediate pipe extendinto and having sealed connection to said outer pipe outside of saidtank nipple, said intermediate pipe being spaced from said inner andouter pipes and constituting a baflle in the space therebetween, closuremeans within the tank between said outer and inner pipes, closure meanswithout said tank between said intermediate and inner pipes, conduitmeans connected to said outer and intermediate pipes without the tankfor circulating through said space between said inner and outer pipes asdirected by said bafile a heated fluid for maintaining the liquid in thetank and in said inner pipe at the elevated temperaturmet surroundingand spaced from said inner pipe and extending from said closure meansbetween said intermediate and inner pipes, and conduit means connectedto said jacket for circulating through the space between it and saidinner pipe a heated fluid for maintaining the liquid in said inner pipeat an elevated temperature.

EDWARD W. KAISER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,251,801 Merrill Jan. 1 1918 1,723,082 Schumann Aug. 6, 19291,727,659 McBride Sept. 10, 1929 1,727,694 Beyer Sept. 10, 19291,801,693 Rufi' Apr. 21, 1931 1,832,412 Newton Nov. 17 1931 2,376,373Merckel May 22, 1945 2,517,821 Allen Aug. 8, 1950 FOREIGN PATENTS NumberCountry Date 624,816 Germany Jan. 17, 1934

